Impacts on psychosocial factors of leaders in lean production systems

Iuri Kiriyama Forte

Federal University of Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brazil.


The aspects that came from Henry Ford's innovation caused some problems, since many parts were produced in large scale for a single car model. The result was huge amounts of unused stock and a high level of waste. In this context, the Toyota Production System or, as it is known, the Lean System (commonly called Lean Production System) emerged in Japan. Although this model proved to be very promising in terms of productivity and optimization of resources, it was identified - also - the need to devote more attention to the well-being of workers, since the Lean Production System (LP) also impacted the Psychosocial Factors (called by the International Labor Organization as aspects of working conditions, organizational structure, and culture, among others). Aim: to verify whether there is an impact on Psychosocial Risks (PR) in professionals who hold leadership positions within the context of companies that have implemented LP. As a research strategy, a questionnaire was developed and applied to evaluate the organizational conditions perceived by these professionals. As a result, it was possible to identify that there is no influence of LP on psychosocial risks. It was concluded that, when identifying evidence of LP impact on well-being in the work environment, these impacts were perceived positively by the respondents.

Keywords: Lean System; Lean Production; Psychosocial Risks.


In 1948, Ohno and Toyoda began to develop the Toyota Production System or TPS (Soares, 2013), later known as Lean Manufacturing, which had two fundamental principles: the elimination of waste and manufacturing with quality (Maximiano, 2005). If on the one hand the Lean system can mean an efficient alternative to reap good results in the production process, on the other hand, it can cause and increase the levels of stress among workers (Conti et al., 2006). Although stress does not represent harm to health – along with anxiety, mood swings, and isolation – it is a symptomatic indicator of physical and emotional damage. Stress can, in this sense, be linked to a biological agent, an environmental condition, a stimulus, or an event (Iol, 2016).

In 1984 the ILO called the work environment factors that can cause stress Psychosocial Factors (PF), bringing attention to the dynamic interaction between the work environment and human factors (Iol, 2016).

Although LP has proven to be a powerful approach for improving productive operational performance, it has been observed that many companies adhering to LP have not been able to achieve a high level of performance (Bortolotti et al., 2015).

Authors Pereira et al. (2014) mention studies citing that the main sources of stress among managers in the modern world are associated with organizational restructuring processes arising from globalization (Isma, 2008).

When considering that workers are permeated by several psychosocial factors, when they occupy a leadership position, increasing their degree of responsibility in the organization, this context can be much more complex. In this sense, it is relevant to verify the psychosocial risks in professionals who exercise a leadership role within the lean production system.

Therefore, the present study intends, by means of a survey, through a customized questionnaire, to identify whether there is an impact on psychosocial risks in professionals who exercise a leadership role within the context of LP.


Lean production system

Some concepts of the Toyota Production System (TPS) were already known to industrial engineers and practiced at Ford during the 1920s. With the help of Taiichi Ohno and Shigeo Shingo, Toyota introduced and continually refined a production system whose goal was to reduce or eliminate non-value added tasks: those for which the customer was not willing to pay.

The Toyota System adopted three main ideas for waste elimination, namely: Workforce rationalization, Just in Time, and Flexible production. By applying these concepts, Toyota managed to reduce production time considerably; activities such as changing the molds on the presses were accomplished in just 3 minutes in Japanese factories, while in Western companies this process took a whole day (Maximiano, 2005).


Liker (2004), in his analysis of Toyota, identified that the lean concept operates on two principles: continuous improvement and respect for people. However, Nordin (2012) ponders that the second principle was not positively understood by senior leaders at Toyota. Continuous improvement (kaizen), in turn, required not only skill, but also a mindset focused on systematically eliminating waste and raising the value of processes. In this sense, the lean concept evolved to the level of knowledge management.

Conti et al. (2006) in a study on the impacts of LP on stress in the workplace highlighted the elements that contribute to stress reduction, as follows:


A study conducted by Barker (1998) with managers found that most of them resist LP implementation due to lack of skills or knowledge on this system. For employees, resistance is linked to lack of commitment or inadequate training.


The term "psychosocial factors" at work encompasses a set of worker's perceptions and experiences in their work environment. It also encompasses economic and social influences that impact the worker. There are studies that explain the nature and interaction between these factors, including the relationship with hierarchies, family or private life circumstances, and cultural elements, such as nutrition, transportation facilities, and interactions with authorities.

The target of Lean was a certain development of the production process, both in terms of quality and productivity control, and in terms of efficiency and effectiveness. The competitiveness strategy causes a relative change in production and labor relations as it transforms the work collective. In this context, workers become each other's inspectors, committed to the company's strategy by acting in an atmosphere of consultation and consensus.


Stenger et al. (2014) expose that the constant technical and technological changes, automation of productive activities, in addition to the leaning in hierarchical levels, aiming at more effective internal flow of information, were factors that contributed to the perception of anxiogenic environments.

For Camelo and Angerami (2008), overload or low workload, lack of control over working activities, and high levels of pressure are psychosocial risks related to work (included in this category), which can lead to stress. In this sense, the authors argue that control over the workday could not only reduce conflict at home and at work, but also reduce the dangers of excessive stress.

The study proposed by Koukoulaki (2014) points out that aspects such as decision-making authority, skill development, autonomy, and job satisfaction, if absent or low, can be a risk factor and generator of effects such as upper limb musculoskeletal disorders, fatigue, tension, and stress.

In this sense, according to Levi (2005), the continuous work-related stress is an important determinant of depressive disorders, besides other impacts on the worker's health, generating consequences such as increased blood pressure and probably contributing to morbidity from heart diseases, triggering of diabetes, exhaustion, weight loss, physical exhaustion, and the onset of other diseases such as stroke and kidney problems due to hypertension.

Leadership in the context of lean production and psychosocial factors

One of the impacts of adopting the LP methodology is on the way people work. While most people will find their work more stimulating as the LP culture is absorbed and production increases, some tasks may become more stressful. This is because one of the essential goals of this production system is to bring responsibility to the bottom of the organizational pyramid. This responsibility means freedom to control one's own work; an advantage, however, that increases the fear of making mistakes that lead to losses, and certainly a disadvantage in our mentality of job insecurity and moderate stimuli for decision-making processes at this level (Moreira, 2011). In a recent study, Seidel and Saurin (2020) define lean leadership as a social process carried out by leaders with personal attributes aligned with lean principles to sustain continuous improvement, and they must be supported by a management system compatible with the internal and external context of the company.

An extensive study conducted by Koukoulaki (2014) supports the relevance of the theme proposed by this article; in it, correlations are presented between the possible impacts -positive or negative- of LP on workers' PR. The research grouped the search terms into three indicators: lean production, work characteristics, and risk factors and health effects, as shown in the following table:


As a result of studies of this nature, theoretical perspectives on the effects of lean production have evolved over the years. When lean production was first introduced, it was presented as an efficient production system with positive effects for workers, increasing their autonomy and empowerment.

Judging by the exposure seen by some authors, we could deduce that in part LP is a contributing factor to the aggravation of psychosocial risks. Koukoulski (2014) highlights research indicating that negative effects observed in workers would be strongly associated with some lean practices, since they intensify work pace. However, lean production cannot be said to be - in itself - harmful. Waste reduction practices are considered the core of Lean production, and without them, a production system can hardly identify itself as Lean. The author also mentions that not all Lean characteristics are harmful, but the main ones can affect negatively if no support – such as social support to the worker – is applied. As highlighted by Conti et al. (2006), it is possible to conclude that LP does not directly represent the impact factor on well-being, but is associated with how it is implemented and how its management is conducted by the leadership.


Outlining the research steps

As a strategy for data collection, we used Survey software, which allows obtaining information about characteristics, actions, or opinions of a certain group of people through a research instrument, usually a questionnaire (Freitas et al., 2000). The choice was due to the fact that it is the most appropriate for answering questions such as "what is happening" or "is it possible to happen". Considering the fundamentals proposed by Gil (2002), the research was divided into five stages: (1) Design; (2) Data collection instrument and Pre-test; (3) Data collection and verification; (4) Data analysis and interpretation; and (5) Presentation of results.

In the Conception stage (1), we sought to specify the research objective, thus allowing us to delimit the subject to be studied and to establish the best research strategy. In this stage a literature review was carried out, selecting articles whose keywords were related to the terms LP and PF.

In the step data collection instrument and pre-test (2), the questionnaire was prepared for information collection, which would be directed to professionals who work in leadership positions. In the data collection and verification stage (3), the platform for inserting the instrument (questionnaire) and applying it to collect information from the target population was defined. In step (4), data analysis was performed. In the step (5), the presentation and interpretation of the research results was carried out, describing the conclusion obtained on the proposed theme.

Questionnaire Development

The questionnaire was divided into three sections that comprise:

1) Company characterization: this section has nine questions about the economic sector in which the company operates, its size in relation to the number of workers and billing, benefits offered, and issues related to human resources behavior, such as turnover and absenteeism. The questions in this section were prepared by the author.

2) Psychosocial aspects: this section has 30 questions addressing the respondent's perception of psychosocial factors inherent to the work environment. The questions addressed aspects related to work organization, hierarchy and interpersonal relationships, support from superiors, control, expectations, work demands, leadership, communication, organizational culture, quantity and quality of work, opportunities, insecurity, compensation, autonomy, learning, and career. The questions formulated for the questionnaire were designed after reviewing the literature on occupational psychosocial factors. The anchor levels of the response alternatives used in this section were "Very rarely or never", "Rarely", "Sometimes", "Often", and "Frequently or always". In some questions, the anchors "Completely", "Somewhat", "Almost never", and "Absolutely not" were used. In the final questions, the anchors used were "Strongly agree", "Agree", "Disagree", and "Strongly Disagree". These differentiations occurred in order to keep the alternatives of the original questionnaire models preserved. The scores given for each anchor level was 1 point.

Table 6 presents the previous works from which the questions in this section of the questionnaire were selected.



3) Respondent profile: This section has 19 questions that dealt with personal aspects and habits of the respondent. The questions used in this section were developed by the author. Quantitative questions were also conducted in this section.

Data Collection and Analysis

Data collection was carried out through the application of the questionnaire sent by e-mail. The "SurveyMonkey®" platform was chosen to insert the questions, develop the layout, and collect the answers. After developing the questionnaire and creating the link to access it, it was sent to approximately 15,000 addresses. In addition, the link was shared via social networks (such as LinkedIn and Facebook) and multi-platform messaging (including WhatsApp and Line). Thus, it was not possible to specify the number of possible respondents.

In all, 138 people answered the questionnaires. The survey was conducted from July 29 to October 21, 2019, and had an average response time of 10 minutes and 54 seconds.

From an initial analysis, it was noticed that not everyone had completed the questionnaire; therefore, certain "filters" were established in order to obtain the sample to be analyzed. The first filter was to verify if the questions were answered in their entirety. Of this total, it was verified that forty-seven respondents had not answered all the questions (N=47). According to some reports informally obtained by the researcher, although the theme was relevant, the length of the questionnaire (with 74 questions) impacted on a completion rate of 62%.

Considering the focus on professionals in leadership positions, we disregarded the data from respondents outside this criterion (N=18). Thus, a final sample of 73 respondents was obtained. Next, this sample was divided between companies with LP and companies without LP, aiming at comparative analyses. To this end, an initial questioning was made as to whether the company in which the respondent worked has the LP implemented or not. Thus, the total population obtained was divided into two samples: one formed by companies which had the LP (N=47) and the other by companies which did not (N=27). The following flow chart describes the steps for obtaining the samples that were used to perform the analysis.


For the data analysis, the statistical computational "tool" was used. For the response alternatives of each question in the questionnaire, a score was adopted, considering 1 for the worst situation and 5 for the best situation. For questions that had four alternative answers, 4 was considered the best situation.

After these steps, the sample means of all the questions were calculated. Comparisons were made between the averages of the two samples of each question, in this case treated as companies that had adopted LP and those without LP. Thus, by analyzing the averages of the two samples of each question, it was already possible to identify the sample that had the most favorable or positive result.

Afterwards, the "t-test" was performed for each question, considering the two samples and their algebraically distinct means. The t-tests are hypothesis tests aiming to compare the means. This was necessary because we wanted to compare the performance of the answers for each question and, therefore, state whether or not the difference between the averages of the two samples was statistically significant.

For the data analysis of the samples and averages, a 95% confidence level was adopted (α 0.05), considering the hypothesis test equal to 0 (zero), that is, that the samples had similar behavior.

After performing the analyses, the t-stat values obtained in the hypothesis tests of the questions were tabulated so that a judgment of the results could be made. Only after performing this analysis, was it possible to say whether the samples had similar performance or significant difference, and thus validate or not LP as an influencing factor in PR.


Characterization of the sample: companies

Table 8 shows that more than 50% of the respondents' companies that adopt LP had revenues exceeding two hundred million reais in 2018. Analyzing the total population of respondents, it was possible to identify that approximately 80% of the companies that adopted LP had positive billing results compared to 66% of the companies that do not use LP. In general, companies that apply LP tend to be larger and have higher revenues. On the other hand, in relation to the benefits offered by the company, the "Career Plan" criterion, companies without LP showed a performance 5% higher than companies with LP. Conversely, in the criteria "Educational Incentives," "Pension Plan", and "Profit Sharing", companies with LP showed a 25% better performance than companies without LP.


Table 9 shows the results concerning personnel turnover and absenteeism, denoting a significant distinction between samples in the first aspect. When analyzing the results concerning turnover, it can be seen that the group of companies with LP showed better results, which may be related to the benefits offered by the companies.


Characterization of the sample: respondents

Table 10 presents a summary of the respondents' characterization. The most visible difference refers to the level of knowledge in LP, which, as expected, is higher in companies with LP. Another interesting finding is that 81.48% of the leaders of companies without LP admitted having some level of knowledge about the system, which indicates a potential for applying LP in these companies.


Perceptions regarding psychosocial factors

Table 11 presents the results regarding the perceptions of psychosocial factors related to organizational culture and work organization. There was no significant difference between the two groups of companies. Nevertheless, considering absolute values, the companies that do not use LP presented better results in seven of the ten questions.

In a study conducted by Conti (2006) with 1,670 workers from 16 factories, the results indicated that workers in factories with LP had heavier workloads, with great difficulty in slacking off or changing work characteristics. It is important to clarify that that study, however, did not indicate the degree of lean implementation or the effects of specific LP practices.


Table 12 shows the results about psychosocial factors associated with personal satisfaction and interpersonal relationships. In only one of the twelve questions was there a difference between the two groups of companies. However, the companies with LP showed a higher average in eleven of the twelve questions. About this factor, Marochi (2002) notes that teamwork in LP allows workers to have a greater vision of the activities they perform and, therefore, of their participation in the productive process. Based on this, the author concludes that in LP the communication process is expanded.


In Table 13, which deals with the autonomy of leadership in process control, there was no significant difference between the two groups of companies.

Regarding autonomy at work, Martinez et al. (2004) recommend actions that increase the autonomy and control exercised by workers over their activities (without generating overload) as a strategy to positively impact the psychosocial aspects at work.


Table 14 presents the perceptions regarding the efforts and achievements made by the leaders. There was no statistically significant difference between the two groups of companies. For Scherer and Ribeiro (2013), the implementation of an LP system should be continuously monitored, promoting recognition to employees for the goals achieved. Araújo and Rentes (2006) point out that changes, even if they are for the better, are difficult for most people; in this sense, when facing change processes, especially those in LP Systems implementations, the authors highlight the importance of reward and recognition systems, as they strengthen mutual trust and respect among people.


In Table 15, three questions were addressed regarding the leaders' expectations about career and the comparison showed that only one question had a significant difference. This result may be associated with the implementation process of LP, which envisions long-term results and - associated with this perspective - seeks to create an environment of development, professional training, and, consequently, stability.



The research conducted allowed us to know and reflect upon the psychosocial risks that leaders may be exposed to, comparing companies that use and do not use LP.

Judging by the results obtained, more than 90% of the questions showed no statistically significant difference between the two groups of companies, i.e., it is not possible to state that LP is a factor that causes some kind of impact on PRRP. The results obtained largely showed that there were similar performance behavior between the companies.

Thus, it is not only the level of implementation of LP that correlates with PRRP, but possibly also the contextual characteristics of each application. According to the literature reviewed, the main mechanism underlying the health effects of LP is work intensification, and in some cases this will be unavoidable. It may be that this does not manifest itself so strongly in leaders, because they do not perform operational and repetitive activities most of the time.

The limitations of this study include: (i) the small number of respondents; (ii) there was no assessment of the level of development of the leaders' competencies, which would allow verifying whether they were more adherent to the style of Lean leaders or traditional leaders; and (iii) it did not consider the degree of maturity of the administration in the team management, the method used for the LP implementation, and the regional economic context. These factors could explain the absence of significant differences between the groups of companies.

As for the possibility of future studies, the following can be highlighted: (i) the expansion of the application of the survey to a larger number of respondents; (ii) the application of the survey in conjunction with a tool to assess the level of development of lean competencies by leaders.


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Received: October 25, 2020

Approved: November 16, 2021

DOI: 10.20985/1980-5160.2021.v16n3.1683

How to cite: Forte, I.K. (2021) Impacts on psychosocial factors of leaders in lean production systems. Revista S&G 16, 3.